rtc.h: add struct udevice declaration

Without this change, including rtc.h solely will cause a build error.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

diff --git a/include/rtc.h b/include/rtc.h
index 7386d52..8aabfc1 100644 (file)
--- a/include/rtc.h
+++ b/include/rtc.h
@@ -18,6 +18,8 @@
 
 #ifdef CONFIG_DM_RTC
 
+struct udevice;
+
 struct rtc_ops {
        /**
         * get() - get the current time